Bombus

Five
species are restricted to relatively few localities,
primarily in the south of Britain. In general, they
tend to be less abundant at each site, but may be
the most abundant species at a few sites. Most bees encountered
will not belong to this group. However, these species are
often likely to occur together at the same sites.

Distinguishing
similar species:
Unlike B. lapidarius
and B. cullumanus,
B. ruderarius queens and workers (1) have the long hairs
of the pollen baskets (corbiculae) on the hind legs red, (2) have
the head much longer than broad, and (3) have the mid basitarsi
with the posterior angle with a spine (see Prys-Jones & Corbet,
1987, 1991); and males (1)
have long antennae, and (2) can be distinguished by their
genitalia.
Unlike the dark form of B.
sylvarum,B.
ruderarius queens and workers have abdominal segments 4 and
5 dull with punctures (see Løken, 1973);
and males can be distinguished by their
genitalia.
Unlike B. pomorum,B.
ruderarius (1) have small body size, (2) have less extremely
long heads (see Løken, 1973);
and the males can be distinguished by their
genitalia.

A small
species with a mid-length tongue, emerging in early spring,
and nesting on the surface of the ground. In its nest structure,
Sladen (1912) describes
it as a 'pocket-making' 'carder bee'. Colonies are small
and relatively mild tempered when disturbed.

England,
Wales, southern and western Scotland, absent from the Scilly
Isles, Orkneys and Shetland. M. Edwards and E. Philp (in Edwards
& Telfer, 2001) conclude
that numbers of this species have declined greatly in recent
years. Data from Alford (1980)
are mapped on a 10 km grid (left) to show local patchiness
and on a 50 km grid (right) to show changes in the regional
pattern (dark blue - post 1960; light blue - pre 1960 only):

The pale form
of this species is unusual for the 'greenish' tint of
the hair in fresh specimens (Sladen, 1912;
Alford, 1975). The
rare dark form has been recorded only a few times in
Sussex (Mortimer, 1922).

Distinguishing
similar species:Fresh pale
B. sylvarum are almost unmistakable in Britain with their
'greenish' yellow hair.
Unlike
pale males of B. ruderarius,
pale males of B. sylvarum (1) have the pale bands more
greenish grey than yellowish brown, (2) have distinct pale fringes
at the posterior of the abdominal segments, and (3) can be distinguished
by their
genitalia.
Unlike
dark B. ruderarius, dark B.
sylvarum
queens and workers have abdominal segments 4 and 5 shiny with
fewer punctures (see Løken, 1973);
and males can be distinguished by their
genitalia.
Unlike B. lapidarius
and B. cullumanus,
dark B. sylvarumqueens
and workers have (1) a long face, and (2) a spine on the mid basitarsus
(see Prys-Jones & Corbet, 1987,
1991); and males can be distinguished by their
genitalia.

A small
species with a mid-length tongue, emerging in late spring,
and nesting below the surface of the ground, sometimes with
a long entrance tunnel, or on the surface of the ground.
In its nest structure, Sladen (1912)
describes it as a 'pocket-making' 'carder bee'. Colonies
are small and relatively mild tempered when disturbed. Workers
have a fast flight with a high pitched buzz.

England
and Wales, absent from Scotland and the Scilly Isles.
It has become rarer in central England (see declines).
Data from Alford (1980)
are mapped on a 10 km grid (left) to show local
patchiness and on a 50 km grid (right) to show changes
in the regional pattern (dark blue - post 1960;
light blue - pre 1960 only):

The rare dark
form has many black hairs intermixed with the orange
hairs on the thorax to appear dark red-brown.

Distinguishing
similar species: Unlike B. pascuorumand B. muscorum,
B. humilis (1) are small with short even hair, (2) usually
have at least a few black hairs above the wing bases (though sometimes
completely absent) but not on the abdomen, (3) the hair at the
front of abdominal segment 2 is much darker than on segment 4,
(4) the hair on abdominal segment 1 is scarcely lighter than that
on the sides of segment 3; and males can be distinguished by their
genitalia.

A small
species with a mid-length tongue, emerging in late spring,
and nesting on the surface of the ground. In its nest structure,
Sladen (1912) describes
it as a 'pocket-making' 'carder bee'. Colonies are small
and relatively mild tempered when disturbed.

England
and Wales, absent from most of Scotland and from
the Scilly Isles. It has become rarer in central
England (see declines).
Data from Alford (1980)
are mapped on a 10 km grid (left) to show local
patchiness and on a 50 km grid (right) to show changes
in the regional pattern (dark blue - post 1960;
light blue - pre 1960 only):

The
dark form is produced by colonies alongside pale-banded
forms and may include many of the individuals (Sladen,
1912). Intermediately
coloured queens are common (which may have the pale
bands much narrowed and more brownish), but this is
rare for workers and males. Despite some recent claims,
B. ruderatus has long been and still is regarded
as a species separate from B.
hortorum by specialists in bumblebee taxonomy
(references in Williams & Hernandez, 2000
[pdf]).

Distinguishing
similar species: Unlike B.
hortorum, B. ruderatus (1) have the white hairs
of the tail usually extending further forwards at the
sides of the abdomen that in the middle, (2) usually
have no yellow hairs at the front centre of abdominal
segment 2, and (3) have the pale bands on the thorax
of equal breadth in the middle (Williams & Hernandez,
2000
[pdf]).
Unlike B. jonellus,
B. ruderatus (1) is very large, (2) has the head much longer
than broad, and (3) queens and workers have a spine on the mid
basitarsus (see Prys-Jones & Corbet, 1987,
1991).Against other
species, males can be distinguished by their
genitalia.

A large
species (especially the very large queens) with a long tongue,
emerging in late spring, and nesting below the surface of
the ground. In its nest structure, Sladen (1912)
describes it as a 'pocket-making' 'pollen-primer' species.
Colonies may be large.

England
and Wales, absent from Scotland and the Scilly Isles.
It has become rarer in central England (see declines).
Data from Alford (1980)
are mapped on a 10 km grid (left) to show local
patchiness and on a 50 km grid (right) to show changes
in the regional pattern (dark blue - post 1960;
light blue - pre 1960 only):

Distinguishing
similar species:B.
hypnorum is unmistakable in Britain with its combination
of an orange-brown thorax and a white tail (see Goulson
& Williams, 2001
[pdf]).
Against other species, males can be distinguished by their
genitalia.

A medium-sized
species with a short tongue, emerging in early spring, and
often nesting above the surface of the ground in cavities
(Løken, 1973).
In its nest structure, it would be placed in Sladen's (1912)
group of 'pollen-storer' species.

Habitat

Gardens,
farmland, woodland glades and edges. More strongly associated
with areas inhabited by people than other bumblebees (Løken,
1973).

British
distribution

First
recorded from Britain in 2001 (Goulson & Williams,
2001
[pdf]). With its broad European distribution,
it probably has the potential to spread throughout
mainland Britain. Data from M. Edwards, D. Goulson,
A. Martin, J. Osborne, B. Pinchen, S. Roberts (in
litt., 2005) are mapped on a 10 km grid (left)
to show local patchiness and on a 50 km grid (right)
to show the regional pattern (dark blue):